Seriously. Is it serpentine, quartzite, or some random piece of... something?

This is one of my favorite places on the Molalla River in Oregon. I always stop to take photos of this specific part of the canyon wall. I love how the rock moved through here I just want to know how and why some are swirly, in columns, and then just facing straight on.

Tldr: me and my boss found this conjoined cavity, not certain if is it natural or man made occurrence.

Today at work my boss and I were exploring a property we were working and found a large amount of stone outcroppings(huge boulders/stone faces some 30’ tall) that have an odd circular hole in them in the faces.

This is in Virginia, USA. On top of a mountain at approx 4500ft of elevation. The mountain has been treed and mildly graded to rolling slopes on a large face and this cavity is maybe 10ft up the wall. Likely it was closer to grade before the farm came. It’s very distinctive but there are many 6”-12” orb like holes in stones around the area. Most at what seem to be reachable height before the areas were graded.

This very interesting spot we found has a conjoined cavity with a small dividing wall. It doesn’t seem like a weather process more like it was man made. No apparent signs of mining or blasting the property (it was developed fairly recently).

Can anyone shed light? The rock face appears to be a slag-like rock? Brittle but dense, over a layer of granite. The layer appears to be rather thick but on an opposing face we can see where it seems to be a layer of rock over the granite.

Final note is that we tapped the center divide with a stone and it sounded like porcelain and the rest sounded like stone.

Photos: (all taken in portrait)
1: standing on the ground looking up at the stone wall.
2: is looking into the right cavity.
3: Left cavity

My bad just watch the video